EXCLUSIVE: Matthew McConaughey and writer-director Gary Ross are the catalysts for a project called Free State Of Jones, which is getting some serious attention from STX Entertainment, the new mini-studio founded by investors TPG Growth, Gigi Pritzker, Hony and Robert Simonds. We hear that company reps, financial partner IM Global (who is handling foreign), and the filmmakers are heading to AFM this afternoon to discuss pre-sales. This is one of many projects STX is considering pushing through as part of its first slate. They are looking to go before the cameras in the first quarter of 2015.

Free State Of Jones is based on the untold and extraordinary story of Newton Knight, the leader of one of the greatest rebellions in Civil War history, and we hear that STX may finance (up to $20M) for the $65M-budgeted story of one of the most controversial men from the that era. McConaughey is in talks to play the Mississippian, who defected from the Confederate Army, banded together with a group of like-minded soldiers, and set out to form their own State known as the Free State Of Jones.

Knight would later have a common-law marriage to a former slave, one of the first outwardly mixed racial unions in the South — unheard of at the time. The rebellious Knight actually fought against the Confederates from within the state and after the war freed children still enslaved after a daring raid.

The project has been a passion play for Ross for several years. Producers on the project are Jon Kilik, Scott Stuber and Ross; CAA is repping the film package. This would not be the first time Knight’s story has been made into a feature: In 1948, director George Marshall directed Van Heflin and Susan Hayward in the the film Tap Roots, which was adapted from a book based a story inspired by the rebel rouser. Of course, this was pre-Stanley Kramer and Guess Who’s Coming to Dinner? so the interracial relationship was not included.

After the death of the defiant Knight, his son wrote a book which described him as a man of character who was passionate in his beliefs and would not be swayed from following his conscience — a man who stood his ground. Yet another relative wrote a book about him, painting him as a traitor. (Yeah, well, the enemy depends upon whose side you’re on, right?)

Both McConaughey and Ross are repped by CAA. The actor is on a tear following his Oscar-winning turn in Dallas Buyers Club, with the HBO series True Detective and the Christopher Nolan-directed Interstellar. Ross, whose directing credits also include The Hunger Games, Seabiscuit and Pleasantville, is separately adapting John Steinbeck’s East Of Eden as a star vehicle for his Hunger Games star Jennifer Lawrence.